Apparatus for calendering continuously produced articles using at least one calender roll

ABSTRACT

Apparatus for calendering continuously produced articles includes a at least one calender roll and a drive having a driveshaft which is constructed in the form of a cardan shaft and operatively connected to the at least one calender roll for rotating the at least one calender roll. In order to maintain the at least one calender roll at a desired temperature, a fluid passageway means is provided for circulation of a temperature control medium. The temperature control medium is hereby introduced into the driveshaft via a rotary hollow-shaft feedthrough which is constructed for distribution of the temperature control medium. The rotary hollow-shaft feedthrough has a first fluid passageway for providing a passageway to the driveshaft, and a second fluid passageway for providing a passageway for discharge of the temperature control medium.

CROSS-REFERENCES TO RELATED APPLICATIONS

This application is a continuation of prior filed copending PCT International application no. PCTIEP2006/050118, filed Jan. 10, 2006, which designated the United States and has been published but not in English as International Publication No. WO 2006/074994 A1 and on which priority is claimed under 35 U.S.C. §120, and which claims the priority of German Patent Application, Serial No. 10 2005 001 782.7, filed Jan. 14, 2005, pursuant to 35 U.S.C. 119(a)-(d), the contents of which are incorporated herein by reference in its entirety as if fully set forth herein.

BACKGROUND OF THE INVENTION

The present invention relates to an apparatus for calendering continuously produced articles.

Nothing in the following discussion of the state of the art is to be construed as an admission of prior art.

German Offenlegungsschrift DE 28 56 096 discloses an extruder and calender combination to produce profiled sheets of elastomer or stamped films of thermoplastic materials. Plastic masses are plasticized by an extruder and further processed by means of a calender which has profiled rolls.

German Pat. No. DE 44 12 862 C1 discloses a roll changer for exchange of rolls on a calender to maintain product tolerance even when exposed to high stress.

It would be desirable and advantageous to provide an improved calendering apparatus to obviate prior art shortcomings.

SUMMARY OF THE INVENTION

According to one aspect of the present invention, an apparatus for calendering continuously produced articles, includes at least one calender roll, a drive having a driveshaft constructed as a cardan shaft and operatively connected to the at least one calender roll for rotating the at least one calender roll, and a rotary hollow-shaft feedthrough having fluid passageway means for circulation of a temperature control medium to maintain the at least one calender roll at a desired temperature, wherein the rotary hollow-shaft feedthrough has a first fluid passageway for providing a passageway to the driveshaft for introduction of temperature control medium into the driveshaft, and a second fluid passageway for providing a passageway for discharge of the temperature control medium from the rotary hollow-shaft feedthrough.

In order to ensure clarity, the term “temperature control” as used throughout the description refers to any tempering process, involving heating or cooling of the at least one calender roll.

The present invention resolves prior art problems by distributing the temperature control medium through the rotary hollow-shaft feedthrough into the at least one calender roll in order to attain a reliable and cost-effective temperature control of the at least one calender roll. Introduction of temperature control medium via the rotary hollow-shaft feedthrough is easy to implement and does not require the use of special mechanisms. By constructing the driveshaft in the form of a cardan shaft, the at least one calender roll can easily be installed and there is no need to precisely align the drive and calender to prevent leakage.

According to another feature of the present invention, the temperature control medium distribution may be realized by an annular gap provided in the rotary hollow-shaft feedthrough. The provision of such a temperature control medium distribution in the rotary hollow-shaft feedthrough simplifies the introduction of temperature control medium into the driveshaft. Suitably, the annular gap is in fluid communication with the first passageway. As a consequence, temperature control medium, which is present in the annular gap for example and passes the periphery of the rotary hollow-shaft feedthrough, can easily be introduced into the driveshaft.

According to another feature of the present invention, the driveshaft may be constructed to allow temperature control medium to flow into the interior of the at least one calender roll. The introduction of the temperature control medium into the at least one calender roll may hereby be implemented via a first conduit which extends, at least in part, within the driveshaft and/or at least one calender roll and is arranged in preferably concentric relationship to the rotation axis of the driveshaft and/or at least one calender roll. This conduit may be designed in various ways, for example as pipeline which extends into the at least one calender roll concentrically within the driveshaft. The conduit may hereby be provided within the driveshaft with an opening in fluid communication with the first passageway of the rotary hollow-shaft feedthrough so that the temperature control medium, introduced through the rotary hollow-shaft feedthrough into the driveshaft, can be accepted by the conduit.

In addition, or as an alternative, the driveshaft may be constructed to allow discharge of temperature control medium from the interior of the at least one calender roll. The removal of temperature control medium from the at least one calender roll may hereby be realized by a second conduit which extends, at least in part, within the driveshaft and/or at least one calender roll and is arranged in preferably concentric relationship to the rotation axis of the driveshaft and/or at least one calender roll.

According to another feature of the present invention, the second conduit for removal of the temperature control medium may be arranged in concentric relationship about the first conduit for introduction of the temperature control medium into the at least one calender roll. The conduit can thus be constructed in the form of a double conduit in which the temperature control medium can be introduced within the double conduit into the at least one calender roll and removed from the at least one calender roll at the outer part of the double conduit.

The provision of the second passageway in the rotary hollow-shaft feedthrough permits an exchange of temperature control medium and establishment a temperature control medium circulation. As a consequence, the temperature control medium, which is removed from the at least one calender roll, can be conducted through the system comprised of the at least one calender roll, conduit and rotary hollow-shaft feedthrough. For example a temperature control unit may be provided for allowing a temperature control of the temperature control medium. The temperature control medium having now a desired temperature can then be fed to the at least one calender roll to thereby establish a temperature control circulation. The second passageway for discharge of temperature control medium may hereby be in fluid communication with the temperature control medium in the driveshaft.

According to another feature of the present invention, a pump may be provided for transport of the temperature control medium. This pump may be designed in any manner known to an artisan.

According to another feature of the present invention, the at least one calender roll may be configured with a changeable sleeve. In this context, it would be of particular advantage, when the side via which the changeable sleeve is replaced would be especially easy to access because the temperature control of the at least one calender roll is realized on the driving side of the at least one calender roll, so that the need for cumbersome assembly and/or disassembly works is eliminated in the event a sleeve needs to be replaced. In addition, or as an alternative, the temperature control of the at least one calender roll could be implemented from the driving side. As a result, when using a changeable sleeve calender, the sleeve is shifted to the side that is not driven. The use of a common rotary feedthrough on this side would be difficult.

BRIEF DESCRIPTION OF THE DRAWING

Other features and advantages of the present invention will be more readily apparent upon reading the following description of currently preferred exemplified embodiments of the invention with reference to the accompanying drawing, in which:

FIG. 1 is a schematic illustration of a calendering apparatus according to the invention, and

FIG. 2 is a schematic, sectional cutaway view, on an enlarged scale, of the calendering apparatus of FIG. 1.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Throughout all the Figures, same or corresponding elements may generally be indicated by same reference numerals. These depicted embodiments are to be understood as illustrative of the invention and not as limiting in any way. It should also be understood that the figures are not necessarily to scale and that the embodiments are sometimes illustrated by graphic symbols, phantom lines, diagrammatic representations and fragmentary views. In certain instances, details which are not necessary for an understanding of the present invention or which render other details difficult to perceive may have been omitted.

Turning now to the drawing, and in particular to FIG. 1, there is shown a schematic illustration of a calendering apparatus according to the invention, including two calender rolls 1, 2 in superimposed configuration. A drive assembly is provided to rotate the calender rolls 1, 2, with the drive assembly having separate drives 3, each having a driveshaft 5 in the form of a cardan shaft for operating the calender rolls 1, 2, respectively. At least one of the calender rolls 1, 2, here calender roll 1 by way of example, is hereby temperature controllable, with the temperature control being realized by a temperature control medium which is introduced through a rotary hollow-shaft feedthrough 4 into a driveshaft 5 that operates the calender roll 1.

As can be seen in FIG. 2, which is a schematic, sectional cutaway view, on an enlarged scale, of the calendering apparatus of FIG. 1, the rotary hollow-shaft feedthrough 4 includes an outer jacket 4′ in which the driveshaft 5 is rotatably supported. Extending concentrically within the driveshaft 5 is a conduit 8 by which temperature control medium is supplied to the calender roll 1. A radial bore 8′ traverses the driveshaft 5 to fluidly connect the conduit 8 with the surface of the driveshaft 5. As a result a passageway 7 is formed on this surface and is in fluid communication with the driveshaft 5 of the calender roll 1. The passageway 7 is thus used for routing temperature control medium, which flows through the annular gap 6 of the rotary hollow-shaft feedthrough 4, into the driveshaft 5.

A temperature control medium distribution 6 is provided in the rotary hollow-shaft feedthrough 4 for distribution of the temperature control medium and is configured in this exemplary embodiment in the form of an annular gap 6. A feed port 6′ in the outer jacket 4′ of the rotary hollow-shaft feedthrough 4 is in fluid communication with the annular gap 6 for supply of temperature control medium. The passageway 7 is always in fluid communication with the annular gap 6, even when the driveshaft 5 rotates.

The driveshaft 5 is hereby designed in such a way that the temperature control medium can be directed into the interior of the calender roll 1. As shown in particular in FIG. 2, this is realized by the conduit 8 which extends within the driveshaft 5 and the calender roll 1 in concentric relationship to the rotation axis of the driveshaft 5 and the calender roll 1.

The driveshaft 5 is furthermore designed in such a way that the temperature control medium can be removed from the interior of the calender roll 1. The removal of the temperature control medium from the calender roll 1 is hereby realized by a conduit 9 which also extends within the driveshaft 5 and the calender roll 1 in concentric relationship to the rotation axis of the driveshaft 5 and the calender roll 1. The conduits 8, 9 are constructed in the non-limiting example of FIG. 2 in the form of a double pipe with two fluid passages, so that temperature control medium is introduced inside the double conduit, i.e. in the conduit 8, into the calender roll 1, and the conduit 9 is configured as hollow conduit, in which the conduit 8 extends, so that temperature control medium issues out of the calender roll 1 at the outer periphery of this double conduit.

The conduit 8 is centered in the driveshaft 5 by a bushing 11 and at the same time sealed by the bushing 11 from the outer conduit 9. The conduit 9 is also connected to the surface of the driveshaft 5 by a radial bore 9′. The rotary hollow-shaft feedthrough 4 has a further passageway 10 which is intended for discharge of temperature control medium from the rotary hollow-shaft feedthrough4 and fluidly connected to the conduit 9 at the surface of the driveshaft 5. As a result, temperature control medium can be discharge from the calender roll 1. The passageway 10 is hereby in fluid communication with an annular gap 6″ which enable a drainage of temperature control medium via a discharge bore 6′″. in the outer jacket 4 of the rotary hollow-shaft feedthrough 4.

As also shown in FIG. 2, the bushing 11 is arranged approximately in midsection of the rotary hollow-shaft feedthrough 4 between the radial bores 8′, 9′. The bushing 11 is hereby arranged, by way of example, on the driving side of the double conduit 8, 9, i.e. in proximal relationship to the drive assembly. Of course, the bushing 11 may be arranged at a different location as well.

Although not shown in detail, the calender roll 1 may be configured with a changeable sleeve which is typically placed over the calender roll 1 to form an exchangeable surface of the calender roll 1. Such an exchangeable surface allows the calender roll 1 to be conformed to different materials being processed and to permit quick replacement, when the surface is worn out.

Further shown schematically in FIG. 1 by way of example is the presence of at least one pump 12 for supply and discharge of the temperature control medium via respective feed and drain pipes. it will be appreciated by persons skilled in the art that the temperature control medium circuit may contain further device which does not appear in FIG. 1, e.g. a heat exchanger. However, this device, like other necessary elements, is not part of the invention, and has been omitted from the Figures for the sake of simplicity.

While the invention has been illustrated and described in connection with currently preferred embodiments shown and described in detail, it is not intended to be limited to the details shown since various modifications and structural changes may be made without departing in any way from the spirit of the present invention. The embodiments were chosen and described in order to best explain the principles of the invention and practical application to thereby enable a person skilled in the art to best utilize the invention and various embodiments with various modifications as are suited to the particular use contemplated.

What is claimed as new and desired to be protected by Letters Patent is set forth in the appended claims and includes equivalents of the elements recited therein: 

1. Apparatus for calendering continuously produced articles, comprising: at least one calender roll; a drive having a driveshaft constructed as a cardan shaft and operatively connected to the at least one calender roll for rotating the at least one calender roll; and a rotary hollow-shaft feedthrough having fluid passageway means for circulation of a temperature control medium to maintain the at least one calender roll at a desired temperature, said rotary hollow-shaft feedthrough having a first fluid passageway for providing a passageway to the driveshaft for introduction of temperature control medium into the driveshaft, and a second fluid passageway for providing a passageway for discharge of the temperature control medium from the rotary hollow-shaft feedthrough.
 2. The apparatus of claim 1, wherein the second fluid passageway is in fluid communication with temperature control medium in the driveshaft.
 3. The apparatus of claim 1, wherein the rotary hollow-shaft feedthrough has an annular gap for distribution of the temperature control medium.
 4. The apparatus of claim 1, wherein the annular gap is in fluid communication with the first passageway.
 5. The apparatus of claim 1, wherein the driveshaft is constructed to allow temperature control medium to flow into an interior of the at least one calender roll.
 6. The apparatus of claim 5, wherein the fluid passageway means includes a first conduit which extends, at least in part, within at least one member selected from the group consisting of the driveshaft and the at least one calender roll, said first conduit being in fluid communication with the first fluid passageway.
 7. The apparatus of claim 6, wherein the first conduit is arranged in concentric relationship to a rotation axis of the at least one member.
 8. The apparatus of claim 5, wherein the driveshaft is constructed to allow discharge of temperature control medium from the interior of the at least one calender roll.
 9. The apparatus of claim 8, wherein the fluid passageway means includes a second conduit which extends, at least in part, within at least one member selected from the group consisting of the driveshaft and the at least one calender roll, said second conduit being in fluid communication with the second passageway.
 10. The apparatus of claim 9, wherein the second conduit is arranged in concentric relationship to a rotation axis of the at least one member.
 11. The apparatus of claim 1, wherein the fluid passageway means includes a first conduit in fluid communication with the first passageway, and a second conduit in fluid communication with the second passageway, said second conduit disposed in concentric surrounding relationship to the first conduit.
 12. The apparatus of claim 11, wherein the first and second conduits form a unitary structure in the form of a double pipe.
 13. The apparatus of claim 1, further comprising at least one pump for transport of the temperature control medium.
 14. The apparatus of claim 1, wherein the at least one calender roll is equipped with a changeable sleeve. 